Prologue: What is Petroleum Coke?

Petroleum coke is a carbonaceous solid-residual byproduct of the oil-refining coking process. Although petroleum coke is a relatively ‘dirty’ substance, this byproduct has potential given its high calorific content (28 MMBtu/ton LHV) and availability, more than 55 million tons in 2005 in the U.S.

Plot Summary

Petroleum coke is a major byproduct that historically has been used as a substitute for coal in power production or as a fuel in cement manufacture. The decreasing quality of crude oil refined in the United States means an increasing amount of petroleum coke is being produced, often with much higher metals and sulfur content.

Our objective is to evaluate a better route for using low quality petroleum coke by converting it into a high purity syngas for our linked acetic acid production team while capturing all of the sulfur, metals, and most of the CO2.

In our process, petroleum coke along with oxygen and steam are fed into an entrained flow gasifier to produce synthesis gas, a combination of carbon monoxide, hydrogen, carbon dioxide and hydrogen sulfide. Sulfur is a poison to downstream chemical production catalysts and must be removed from syngas to ppm levels.

Overall ReactionsPetcoke + O2 + H2O CO + H2 + CO2 + H2S + Ash

Chapter 4: Syngas Preparation Due to the relatively high amount of hydrogen

sulfide and a ratio of CO to H2 that is not conducive to acetic acid synthesis, multiple sub processes are required to clean the syngas and adjust the CO to H2 ratio.

The Hydrogen Sulfide Removal and Claus Process are able to selectively remove H2S from the syngas and covert it to elemental sulfur.

The Water Gas Shift (WGS) allows the ratio of H2 to CO to be adjusted to 2.5.

Syngas Production From Petroleum Coke GasificationFrom Low to High: A Story About Petroleum Coke and its Journey to Value

Authors: Russell Cabral, Tomi Damo, Ryan Kosak, Vijeta Patel, Lipi Vahanwala Editors: Bill Keesom – Jacobs Consultancy; Jeffery Perl, PhD UIC Dept. of Chemical Engineering

Conclusion With proper treatment petroleum coke can be

converted from a low quality byproduct to a high quality syngas that can be used in chemical production to form a highly profitable product, in this case acetic acid. The Shell Gasifier, which is the backbone of the process, converts petcoke into a syngas. The biggest hurdle is the removal of sulfur and shifting the H2 and CO ratio, which is readily accomplished by the H2S absorption and WGS processes which are able to remove the impurities that label petcoke as ‘dirty’. In addition, capturing the CO2 from this process significantly reduces its carbon footprint.

Chapter 7: Economics

Chapter 1: GasificationGasification is the process of

converting a carbon-rich feedstock into a highly usable synthesis gas. The term syngas means the gas is mainly composed of carbon monoxide and hydrogen but will contain impurities like HsS.

In our process the syngas produced must be cleaned, separated, and shifted to the proper ratio of carbon monoxide to hydrogen while utilizing the byproducts.

Ultimate AnalysisComponent

Weight Percent

Carbon 83.3Hydrogen 4.00Nitrogen 1.49Sulfur 6.14Oxygen 4.44

Entrained Flow Gasifier

(http://www.netl.doe.gov/technologies/coalpower/gasification/gasifipedia/4-gasifiers/4-1-2-3_shell.html)

Chapter 2: Process Overview

Chapter 5: Carbon Dioxide Capture

Carbon Dioxide is separated from the syngas through two absorption columns using Selexol as solvent. Carbon dioxide is then flashed off of the solvent and made capture ready. Capturing CO2 from this process reduces the greenhouse gas footprint to levels similar to that of bio feedstock based processes.

Chapter 6: Plant Layout• 4923 Port Rd.,

Pasadena, TX

• 2.5 Miles West of Trinity Bay

• Existing Roads and Railroads

• 140 Acres with Acetic Acid Production (Team Golf)

V Ni F Cu Mg Se Be Pb As Cd Hg

PPM325

-230

0

165-580 11 3.5 2.4 <2 1.5 .6 .3 .1 <.0

1

Proximate AnalysisComponent

Weight Percent

Fixed Carbon 84.8

Moisture 6.00Volatile Matter 8.60

Ash 0.6

*Block flow diagram with stream data from our Aspen Plus steady state simulation

Average Metal Makeup

Chapter 3: Aspen Plus Simulation

$182, 57%

$20, 6%

$46, 14%

$73, 23%

Capital Cost Distribution ($321MM Total) Equipment Direct Cost Land Cost Engineering Cost

Plant Construction

Total Equipment + Installation Cost

Process Cost in MM$

Gasification Process 135H2S Removal 14Claus Process 3CO2 Capture 26WGS Reaction 4Total Direct Cost 182

Economic AnalysisCapital Cost $ 321 MMInterest Rate on the Loan 8.00 %Inflation 3.00 %Syngas Price ($/ton) $ 457.80 Sulfur Price ($/ton) $ 70NPV $1,534

MM IRR 29.79 %Payback Period ~ 5.2

years

Overall Process Simulation